A time-domain code, SEALOADS, has been developed to predict ship motion, sea load and hydrodynamic pressure distribution of ship. The theoretical background of SEALOADS is outlined. Computations were carried out for a frigate in regular waves at various wave headings and steepnesses for different forward speeds. The predictions of heave, roll, pitch, shear force and bending moment, and pressures at several locations were presented. The validation study of computed results was carried out by comparing with experimental data from a hydroelastic model of the frigate.